A campaign group is to consult its lawyers over the statement in the Conservative election manifesto that it intends to expand Heathrow .

HACAN (Heathrow Association for the Control of Aircraft Noise), the residents’ group which opposes expansion, claims that the current consultation - which still has a week to run - was invalidated with the pledge on Thursday (May 18) that the Conservatives would proceed with a third runway.

The manifesto reads: “We are investing to reduce travel time and cost, increase capacity and attract investment here in the UK.

“We will continue our programme of strategic national investments, including High Speed 2, Northern Powerhouse Rail and the expansion of Heathrow Airport - and we will ensure that these great projects do as much as possible to develop the skies and careers of British workers.”

This left Mr Stewart unhappy.

He said: “The manifesto announcement seems to have pre-empted the result of the consultation which doesn’t close until next Thursday.